Hi from Texas

Other way around…

Repeat filling to each next line and glancing until the dot is completely obscured and the tube looks like the “End Test” picture below. When the dot is completely obscured, note the number next to the fill line on your CYA view tube, then add 10 to that number. This is your CYA level in parts per million (ppm). CYA should be recorded as a multiple of 10 (i.e. 30, 40, 50, etc.) in PoolMath, to the forum, and with our FC/CYA tool.
For example, if your dot is not obscured at 60, but when you fill to the next line (50) it is obscured, then the transition from not obscured to obscured happened between 60 and 50. Because the scale is not linear between the lines, you cannot determine CYA between the lines, so we round up to the next higher 10. In this example, your CYA is 60.
 
  • Like
Reactions: PoolStored